Railway signaling and train-stopping system



June 25, 1929. 'c, LAY 1,718,568

RAILWAY SIGNALING AND TRAIN STOPPING SYSTEM Filed Sept. 11, 1928 INV ENTOR I H-wz ATTORNEY Patented June 25, 1929.

UNITED STATES PATENT OFFICE.

CHARLES H. LAY, OF SOUTH PASADENA, CALIFORNIA, ASSIGNOR TO THE UNION SW'ITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY SIGNALING AND TRAIN-STOPPING SYSTEM.

Application filed September 11, 15-228.

My invention relates to railway signaling and train stopping s 'tems, and has for an object the provision of a system of this character which provides a special permissive indication and special permissive control of the train stopping device without the necessity for addit ional relays or line wires.

I v ll describe two forms of systems embodyi g my invention, and will then point out the novel features thereof in claims.

in the accompanying drawings, Fig. 1 is a drr 'rannnatic viewshowing one form of railwa v signaling and train stopping system emlJOL yingmy invention. Fig. 2 is a fragmentary dn rannnatic view showing a modification of the signaling portion of the system shown in Fig. 1.

Similar reference characters refer to similar parts in each of the views.

Referring first to Fig. 1, the reference characters 1 and 1 designate the track rails of a railway track along which tratlic normally moves in the direction indicated by the arrow. These rails are divided by insulated joints 2 to form a plurality of track sections AB, BG. etc.

Each track section is provided with a track circuit comprising a source of current connected with the rails at the exit end of the section and a track relay connected with the rails at the entrance end of the section. As here shown, the source of current for each trac section is a transformer which is designated by the reference character L,with an exponent corresponding to the location, the secondary of which is connected across the track rails, and the primary of which is connectcd with a source of alternating current which is not shown in the drawing. The track relay for each section is designated by the reference character F with an exponent corresponding to the location, and, as here shown, is a single winding relay; in actual practice this relay will usually be of the twowinding type, one winding of which is connected across the track rails and the other windin :of which is constantly supplied with alterna ing current of the same frequency as that which is furnished to the track rails by the transformers F.

Each track section is provided with a home relay designated by the reference character H with an exponent corresponding to the locati on, and also with a distant relay designated Serial No. 305,158.

by the reference character K with an exponent corresptmding to the location.

Each home relay H is controlled by the associated track relay, and also by the track relays for the two sections next in advance, For example, the circuit for home relay H is from terminal B of a suitable source of current, through front contact 3 of track relay v F, front contact st of track relay F front contact 5 of track relay F and the winding of relay H to terminal 0 of the same source of current. It follows that relay H is energized when and only when track relays F and F are energized, that is, when and only when track sections BC, CD, and D-E, are unoccupied.

Each distantrclay K is controlled by the home relay H for the section next in advance. The circuit for relay K for example, is from terminal B through front contact 8 of home relay H and the winding of relayK to terminal It follows that each distant relay K is energized when and only when the home relay for the next section in advance is energized, that is, when and only when the three track sections in advance of the section with which the distant relay is associated are unoccupied.

Lo ated adjacent the entrance end of each track section is a signal which is designated by the reference character S with an exponent corresponding to the location. Each of these signals comprises three lamps G, Y and R, which lamps are adapted, when lighted, to indicate proceed, aution and stop, respectively. As will hereinafter appear, lamps Y and R are simultaneously lighted under certain conditions, and when this is so the signal gives what I will term a per-mis sive indication. For convenience I will hereinafterrefer to the lamps G, Y and R as the green lamp, the yellow lamp, and the red lamp, respectively. v

Referring particularly to signal 8*, the circuit for the green lamp G is from terminal B, through the front point of contact 11 of home relay H the front point of contact 12 of distant relay K and green lamp G to terminal 0. It will be seen, therefore, that the green lamp is lighted when and only when the associated home and distant relays are both energized. The yellow lamp Y is provided with a circuit which includes the front pointof contact 11 of home relay H andthe back point of contact 12 of distant relay K it follows that this lamp will be lighted when the home relay, is energized and the distant relay is de -energized. The red lamp It is provided with a circuit which includes the back j point of contact 11 of home relay H and it V and B-C are unoccupied, so that home relay H is tie-energized but track relays F and F are energized. The red lamp llis lighted at the same time, because its circuit is closed at the back point of contact 11 of home relay H The signal then gives the pern'iissive indication. It will be noted that the auxiliary circuit for lamp Y includes a portion of the circuit for the, home relay for the section next'in the rear, and so I am able to obtain this additional indication without the necessity for any additional wires or relays.

The circuits for each signal S are similar to the circuits just explained for signal S Each track section is provided with an automatic train stopping device designated by the reference character T with an exponent corresponding to the location. Each of these devices, in the form here shown, comprises a trip arm which occupies its stopping position when Clo-energized, but which is moved into an ineffective position when energized. Each trip arm is located a short distance in advance of the entrance end of the associated section,

and this distance may, for example, be about 16 feet. The reason for this location will be explained hereinafter.

Referring, for example, to trip arm T this arm is provided with a main circuit which passes from terminal B, through back contact 7 of track relay F front contact 10 of home relay H and the operating mechanism of the trip arm T to terminal 0. It follows that this trip arm is normally deenergized because its main circuit is opened at contact 7 of track relay F, but that the trip arm becomes energized when a train enters section AB, provided that home relay H is energized, that is, provided that sections BC, CD and D-E are unoccupied. Trip arm T is provided with an auxiliary circuit which passes from terminal B, through front contact 3 of track relay F back contact 6 of track relay F and the operating mechanism of trip arm T to terminal 0. It follows that if section DE is occupied by a train, but sections BC and CD are unoccupied, home relay H will be deenergized, so that the main circuit for trip arm T is opened, but the auxiliary'circuit for this trip arm will become closed at back contact (3 of track relay F as soon as a second train enters section B-C. The trip arm requires a certain amount of time, however, to move from its train stopping position to its ineffective position, and, consequently, if the train is moving at more than a fixed low speed, the trip arm will not move to its ineffective position before it is reached by the train and so the train will be stopped. It will be noted that the auxiliary circuit for trip arm T includes a portion of the circuit for home relay H and so I am able to accomplish the permissive control of the trip arm without the necessity for additional relays and wires.

As shown in the drawing, the section immediately to the right of point E is occupied by a train Q, so that track relay F is deenergized. The circuit for home relay H is open at contact 5 of track relay F so that this home relay is likewise de-energized. The red lamp R of signal S is lighted, because its circuit is closed at the back point of con tact 11 of home relay H The circuit for home relayH is opened at contact at of track relay F with the result that this home relay is tie-energized and the red lamp R of signal S is lighted, so that this signal indicates stop. The circuit for home relay H is open at contact 3 of relay F so that this home relay is also Lie-energized, with the result that the red lamp R of signal S is lighted. The auxiliary circuit for the yellow lamp Y of signal S is closed, however, so that this lamp is also lighted, with the result that signal S gives the permissive indication. Home relay H is energized, but distant relay K is (lo-energized because home relay H is tie-energized. It follows that the yellow lamp Y of signal S is lighted, so that this signal indicates caution, Both the home relay H and the distant relay K are energized, so that the green lamp G of signal S is lighted and this signal indicates proceed.

I will now assume that while train Q, occupies the section immediately to the right of point E, a second train enters section A-B. lVhile the second train was in the section to the left of. point A, trip arm T was moved to its ineffective position, because of the de-energization of the track relay for the. section to the left of point A. As long as the train occupies the section AB, the trip arm T will be held in its ineffective position by virtue of its auxiliary circuit through contact 3 of track relay F and back contact '6 of track relay F". It follows that the second train will not be stopped by the trip arm T lVhile the train is in section A-B, the main circuit for trip arm T will be closed at contact 7 of track relay B, so that when the train enters section BC it will not be stopped by this trip arm; the trip arm will remain in its in Cir effective position while the train occupies section BC. Trip arm T will not be energized while the second train occupies section BC, because the main circuit for this trip arm is open at contact 10 of home relay H IVhcu the train enters section CD, however, the de-energization of track relay F will close the auxiliary circuit for trip arm T at contact 6, and, consequently, if the train is moving slowly enough in response to the permissive indication given by signal S this trip arm will be moved to its ineffective position before it is reached by the train. If, however, the train is exceeding a given low speed limit, it will reach trip arm T before this arm moves to its ineffective position and so the train will be stopped. Trip arm T is de-energized because its main circuit is open at contact 10 of home relay H and when the second train enters section DE this trip arm will remain de-energized because its auxiliary circuit is open at. contact 3 of track relay F It follows that if the second train attempts to pass signal S it will be stopped by the trip arm T Referring now to Fig. 2, the apparatus shown in this view is the same as that shown in Fig. 1, except that the permissive indication is given by an additional yellow lamp Y instead of by the usual caution lamp Y. The caution lamp Y is provided with only one circuit, which circuit includes the back point of contact 12 of distant relay K and the front point of contact 11 of home relay H The auxiliary yellow lamp Y is controlled by the back contact 9 of home relay H the front contact 4 of track relay F and front contact 3 of the track relay for the section next in advance. It follows that when sections C-D and DE are u1'1occupied,but the section to the right of point E is occupied, both the red lamp R and the yellow lamp Y of signal S will be lighted, so that this signal will give the permissive indication.

Although I have herein shown and described only two forms of systems embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track divided into sections, a track circuit including a track relay for each section, a home relay and a distant relay for each section, a circuit for each home relay controlled by the track relay for the associated section and by the track relays for the two sections next in advance, a circuit for each distant relay controlled by the home relay for the section next in advance; a signal for each section comprising green, yellow and red lamps; a green lamp circuit for each signal including a front contact of the associated home relay and a front contact of the associated distant relay, a yellow lamp circuit for each signal including a front contact of the associated home relay and a back contact of the associated distant relay, a red lamp circuit for each signal including a back contact of the associated home relay, and an auxiliary yellow lamp circuit for each signal including a back contact of the associated home relay and front contacts of the track relays for the associated section and the section next in advance.

2. In combination, a stretch of railwa 1 track divided into sections, a track circuit including a track relay for each section, a home relay and a distant relay for each scction, a circuit for each home relay controlled by the track relay for the associated section and by the track relays for the two sections next in advance, a circuit for each distant relay controlled by the home relay for the section next in advance; a signal for each section comprising green, yellow, and red lamps; a green lamp circuit for each signal including a front contact of the associated home relay and a front contact of the associated distant relay, a yellow lamp circuit for each signal including a front contact of the associated home relay and a back contact of the associated distant relay, a red lamp circuit for each signal including a back contact of the associated home relay, an auxiliary yellow lamp circuit for each signal including a back contact of the associated home relay and front contacts of the track relays for the associated section and the section next in advance, an automatic train stopping device for each section located in advance of the entrance end of the section, a normal circuit for each device including a. front contact of the associated home relay, and an auxiliary circuit for each device including a back contact of the associated track relay and a front contact of the track relay for the section next in advance.

3. In combination, a stretch of railway track divided into sections, a track circuit including a track relay for each section, a home relay for each section, a circuit for each home relay controlled by the track relay for the associated section and by the track relay for the two sections next in advance, an automatic train stopping device for each section located in advance of the entrance end of the section,

a normal circuit for each device including a front contact of the associated home relay, and an auxiliary circuit for each device including a back contact of the associated track relay and a front contact of the track relay for the section next in advance.

4. In combination, a stretch of railway track divided into sections, a track circuit including a track relay for each section, a home relay and a distant relay for each section, a

circuit for each home relay controlled by the track relay for the associated section and by the track relays for at least two sections in advance, a circuit for each distant relay controlled by the home relay for the section next in advance; a signal for each section comprising green, yellow, and red lamps; a green lamp circuit for each signal including a front contact of the associated home relay and a front contact of the associated distant relay, a yellow lamp circuit for each signal including a front contact of the associated home relay and a back contact of the associated distant relay, a red lamp circuit for each signal including a back contact of the associated home relay, and an auxiliary yellow lamp circuit for each signal including a back contact of the associated home signal and a front contact of the track relay for the associated section as well as a front contact of each track relay which controls the associated home relay except the last one in advance.

5. In combination, a stretch of railway track divided into sections, a track circuit including a track relay for each section, a home relay and a distant relay for each section, a circuit for each home relay controlled by the track relay for the associated section and by the track relays for at least two sections in advance. a circuit for each distant relay controlled by the home relay for the section next in advance; a signal for each section comprising green, yellow and red lamps; a green lamp circuit for each signal including a front contact of the associated home relay and a front contact of the associated distant relay, a yellow lamp circuit for each signal including a front contact of the associated home relay and a back contact of the associated distant relay, a red lamp circuit for each signal in eluding a back contact of the associated home relay, an auxiliary yellow lamp circuit for each signal including a back contact .of the associated home relay and a front contact of the track relay for the associated section as well as front contacts of all track relays which control the associated homerelay except the last one in ad ance, an automatic train stopping devicefor each section located in advance of the entrance end of the section, a normal circuit for each device including a front contact of the associated home relay, and an auxiliary circuit for each device ineluding a back contact of the associated track relay and a front contact of each track relay which controls the associated home relay except the last one in advance.

In testimony whereof I aflix my signature.

CHARLES H. LAY. 

